Most pistols come from the factory with iron sights. Typical iron sights provided on a pistol include a front post and a rear notch which must be aligned to aim the pistol. Mounting an optical sight on a pistol offers a shooter several advantages over using iron sights alone. Optical sights provide a simple sight picture comprised of a single illuminated aiming point in place of the front post and rear notch of iron sights. In this way, a shooter's accuracy and/or speed with a pistol may improve. Further still, a shooter may be able to aim with the illuminated aiming point of an optical sight in environmental conditions that would make visual alignment of the iron sights difficult or impossible, low light conditions for example.
However, given the design of most pistols, attaching an optical sight may be difficult to do. In order to accommodate an optical sight, the slide of the pistol may need to be permanently modified in order to receive an optical sight thereon, milled for example. If the user decides to switch to a new optical sight, further modifications to the pistol may be required. In some instances, the pistol may not be suitable for further modification.